Tuning the donor properties of bipyridyl-substituted phosphines by metal ion encapsulation & Photocatalytic synthesis of 6H-benzo[c]chromenes from S-aryl sulfonium salts

Karreman, Steve

dc.contributor.advisor	Alcarazo, Manuel Prof. Dr.
dc.contributor.author	Karreman, Steve
dc.date.accessioned	2022-11-09T15:50:58Z
dc.date.available	2022-11-16T00:50:11Z
dc.date.issued	2022-11-09
dc.identifier.uri	http://resolver.sub.uni-goettingen.de/purl?ediss-11858/14332
dc.identifier.uri	http://dx.doi.org/10.53846/goediss-9546
dc.language.iso	eng	de
dc.rights.uri	http://creativecommons.org/licenses/by/4.0/
dc.subject.ddc	540	de
dc.title	Tuning the donor properties of bipyridyl-substituted phosphines by metal ion encapsulation & Photocatalytic synthesis of 6H-benzo[c]chromenes from S-aryl sulfonium salts	de
dc.type	doctoralThesis	de
dc.contributor.referee	Alcarazo, Manuel Prof. Dr.
dc.date.examination	2022-09-30	de
dc.description.abstracteng	This work is divided into two parts. The first part introduces a novel approach for the synthesis of cationic phosphine ligands by metal ion encapsulation. In this context, multidentate heterophosphines encapsulate a cationic metal ion and change their electronic and structural properties on the uncoordinated phosphorus. The influence of the implemented cationic charge on the donor ability of the phosphines was investigated using Tolman electronic parameters and 1JPSe coupling constants, demonstrating the low net donor ability of the ligand class. Subsequent P-coordination to platinum(II) or gold(I) led to the synthesis of bimetallic complexes. After activation of the corresponding platinum(II) bimetallic complexes, high reactivity was observed in the pi-acid catalyzed hydroarylation of propargyl ethers. The second part focusses on a two-step protocol converting specially designed benzyl phenyl ethers into tricyclic 6H-benzo[c]chromenes. The first step consists of a selective CꟷH sulfenylation, while the second step involves a photoredox-catalyzed cyclization. The photocatalytic reaction proceeds via a one-electron reduction of the corresponding sulfonium salt, selective SꟷAr(exo) bond cleavage and subsequent radical 5-exo-trig cyclization, reoxidation, ring expansion and rearomatization. The proposed mechanism is supported by several studies. Furthermore, the methodology can be used to enable double cyclizations, to build up helical structures and provides a basis for the synthesis of pyrylium salts.	de
dc.contributor.coReferee	Schneider, Sven Prof. Dr.
dc.contributor.thirdReferee	Simeth, Nadja A. Prof. Dr.
dc.contributor.thirdReferee	John, Michael PD Dr.
dc.contributor.thirdReferee	Frauendorf, Holm Dr.
dc.contributor.thirdReferee	Walker, Johannes C. L. Prof. Dr.
dc.subject.eng	cationic phosphines	de
dc.subject.eng	encapsulation	de
dc.subject.eng	pi-acid catalysis	de
dc.subject.eng	platinum catalysis	de
dc.subject.eng	benzo[c]chromenes	de
dc.subject.eng	photoredox catalysis	de
dc.subject.eng	sulfenylation	de
dc.subject.eng	cyclization	de
dc.subject.eng	sulfonium salts	de
dc.identifier.urn	urn:nbn:de:gbv:7-ediss-14332-1
dc.affiliation.institute	Fakultät für Chemie	de
dc.subject.gokfull	Chemie (PPN62138352X)	de
dc.description.embargoed	2022-11-16	de
dc.identifier.ppn	1821399587
dc.notes.confirmationsent	Confirmation sent 2022-11-10T06:15:01	de

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